TWI570176B - Liquid crystal polyester composition, method for producing liquid crystal polyester composition, and molded body - Google Patents

Description

Liquid crystal polyester composition, method for producing liquid crystal polyester composition, and molded body

The present invention relates to a liquid crystal polyester composition, a method for producing a liquid crystal polyester composition, and a molded body.

This case is based on the Japanese Patent Application No. 2012-063666, which was filed on March 21, 2012. It claims priority and the content is used here.

Conventionally, a liquid crystal polyester composition composed of a liquid crystal polyester, a fibrous filler, and a plate-shaped filler has been known.

For example, Patent Document 1 discloses a liquid crystal polyester (A) having a flow temperature of 310 ° C to 400 ° C and a liquid crystal polyester (B) having a flow temperature of 270 ° C to 370 ° C, with respect to liquid crystal polymerization. 100 parts by mass of the ester (A), and the liquid crystal polyester composition obtained by blending the liquid crystal polyester (B) in an amount of 10 to 150 parts by mass, relative to the total amount of the liquid crystal polyester (A) and the liquid crystal polyester (B) The liquid crystal polyester composition obtained by blending 15 to 180 parts by mass of the inorganic filler in a fibrous form and/or a plate shape.

Patent Document 2 discloses a liquid crystalline resin composition containing 100 parts by mass of a liquid crystalline resin, a fibrous filler, and a number average. The composition of the scaly filler having a particle diameter of 8 μm or more, the blending amount of the fibrous filler is more than the blending amount of the scaly filler, and the total amount of the fibrous filler and the plate filler is 70 to 150 mass. A liquid crystalline resin composition.

Patent Document 3 discloses a liquid crystal polyester composition comprising a liquid crystal polyester, a fibrous filler having an average fiber diameter of 5 to 30 μm and a weight average fiber length of 250 to 350 μm, and 10 to 20% by mass, and The composition of the plate-shaped filler is 30 to 40% by mass, and the total amount of the fibrous filler and the plate-shaped filler is 40 to 60% by mass of the liquid crystal polyester composition based on the entire composition.

Patent Document 4 discloses a liquid crystal polyester composition which is composed of a liquid crystal polyester, a fibrous filler having a weight average fiber length of 250 to 600 μm, 10 to 25% by mass, and a plate filler of 25 to 30% by mass. In the total amount of the fibrous filler and the plate-like filler, the liquid crystal polyester composition is 40 to 50% by mass based on the total amount of the composition.

Patent Document 1 Japanese Patent Publication No. Hei 10-219085

Patent Document 2, JP-A-2007-254716

Patent Document 3 International Publication No. 2008/023839

Patent Document 4, JP-A-2010-003661

Invention disclosure

In the general resin composition, a molding failure for suppressing the molded body obtained by using the resin composition is sought. Imagine the formation of the bad system Such as raw edges or short hair. The "burr" is a problem caused by the curing of the resin leaking from the parting line of the mold during molding. The "short hair" is insufficient filling of the resin material during molding, and the accompanying phenomenon General name (refer to Osaka City Industrial Research Institute, Plastics Book Compilation Committee, Plastic Technology Association, "Plastic Reading Book 19th Edition", Stock Company Plastics Age, May 20, 2002, p.255).

The burrs are the main cause of the excessive fluidity of the molten resin composition in the mold to be used, and the fluidity of the resin composition melted by the short hair system is mainly a cause. Therefore, when the fluidity at the time of melting of the resin composition (hereinafter, referred to as "melt flowability") is changed, the frequency of occurrence of burrs and short hairs fluctuates simultaneously. For example, when the fluidity at the time of melting of the resin composition is increased, short hair can be suppressed at the time of injection molding, but the resin composition is likely to leak from the mold, so that burrs are likely to occur.

In the following description, the relationship between the amount of occurrence of burrs and short hair (frequency of occurrence) in the resin composition is referred to as "flow balance" of the resin composition. The "flow balance" is a good balance between the resin composition and the melt flowability which suppresses the occurrence of burrs and the occurrence of short hair (simultaneous suppression). The "flow balance" difference is that at least either of the burrs or the short hair is not suppressed, and the melt fluidity which causes the formation failure is obtained.

Further, in the resin composition, not only a good flow balance but also the strength of the obtained molded body is maintained or improved. However, in order to increase the strength of the molded body, when various fillers are added to the resin composition, the fluidity at the time of melting of the resin composition is lowered by the influence of the filler, and the flow balance is deteriorated. For example, adding various filler materials to the resin composition can be upgraded into The strength of the body, but due to the influence of the filler, the fluidity at the time of melting of the resin composition is lowered, and short hair is easily generated.

In particular, the liquid crystal polyesters used in the above-mentioned Patent Documents 1 to 4 are likely to be burrs due to the flow during melting, and the resin is aligned during molding, and the strength of the molded body is anisotropic, so that it is emitted. It is known that the welded portion of the formed molded body is susceptible to cracking. The suppression of the occurrence of cracks in the liquid crystal polyester composition molded article described in the above Patent Documents 1 to 4 (hereinafter, referred to as "crack resistance"), and the realization of good flow balance at the time of melting Coexistence may not be sufficient.

An object of the present invention is to provide a liquid crystal polyester composition which has excellent crack resistance and good flow balance and which is excellent in a molded article. Further, an object of the present invention is to provide a method for producing such a liquid crystal polyester composition and a molded article formed by using a liquid crystal polyester composition.

One aspect of the present invention provides a liquid crystal polyester composition comprising 100 parts by mass of a liquid crystal polyester, and a total of 65 parts by mass or more and 100 parts by mass or less of the fibrous filler and the plate-like filler, and the fibrous filler coefficient The average fiber diameter is 5 μm or more and 15 μm or less, and the number average fiber length is longer than 200 μm and less than 400 μm, and the mass ratio of the fibrous filler to the plate-shaped filler is 3 or more and 15 or less, and the flow initiation temperature is 250. Less than 314 ° C above °C.

In one aspect of the invention, the liquid crystal polyester is preferably a repeating unit represented by the following formula (1), a repeating unit represented by the following formula (2), and a formula (3) Repeat unit; (1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-X-Ar ³ -Y-

Here, Ar ¹ represents a phenyl, anthracenyl or a phenyl group; and Ar ² and Ar ³ each independently represent a phenyl, anthracene or a phenyl group or a formula (4) In the formula, X and Y each independently represent an oxygen atom or an imine group, and the hydrogen atom of the above group represented by Ar ¹ , Ar ² or Ar ³ may independently be a halogen atom, an alkyl group or an aryl group. Substituted; (4)-Ar ⁴ -Z-Ar ⁵ -

Here, Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthyl group.

The Z system represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group or an alkylene group.

In one aspect of the invention, the liquid crystal polyester is preferably a repeating unit represented by the above formula (1), a repeating unit represented by the above formula (2), and the formula (3). The repeating unit is configured; the Ar ¹ is a liquid crystal polyester (A) having a phenyl group and a repeating unit represented by the above formula (1), and a repeating unit represented by the above formula (2) It is composed of a repeating unit represented by the above formula (3), and the above Ar ¹ is a mixture of liquid crystal polyesters (B) of 2,6-anthranyl group.

In one aspect of the invention, it is preferable that the liquid crystal polyester (A) is contained in an amount of 20 parts by mass or more based on 100 parts by mass of the liquid crystal polyester.

In one aspect of the invention, the fibrous filler is at least one selected from the group consisting of glass fibers, ettringite whiskers, aluminum borate whiskers, and potassium titanate whiskers.

In one aspect of the invention, it is preferable that the plate-shaped filler is one or both of mica and talc.

In one aspect of the invention, it is preferable that the plate-shaped filler has a volume average particle diameter of 10 μm or more and 30 μm or less.

According to one aspect of the invention, there is provided a method for producing a liquid crystal polyester composition, comprising: 100 parts by mass of the liquid crystal polyester, and a total of 65 parts by mass or more and 100 parts by mass or less of the fibrous filler raw material and the plate-shaped filler. a step of melt-kneading the mixture, wherein the filler material has an average fiber diameter of 5 μm or more and 15 μm or less and a number average aspect ratio of 100 or more, and the extruder used in the step of melt-kneading includes a cylinder and is disposed in the cylinder a screw in the cylinder, wherein the cylinder has a first supply port and a second supply port located on the downstream side in the extrusion direction from the first supply port; and an effective length (L) of the screw-type screw to the diameter of the screw (D) a ratio (L/D) of 15 or more and 65 or less, and 50% by mass or more of the total supply amount of the liquid crystal polyester and 50% by mass or less of the total supply amount of the filler raw material are supplied from the first supply port. The second supply port supplies the residual amount of the liquid crystal polyester, and the residual amount of the filler material and the total amount of the plate-shaped filler, and melts and kneads.

In the present specification, the "filler material" means a fibrous material which is broken during melt-kneading and which is a fibrous filler contained in the liquid crystal polyester composition.

Moreover, one aspect of the present invention provides the liquid crystal polyester composition described above, or a molded body obtained by injection molding a liquid crystal polyester composition produced by the above-described method for producing a liquid crystal polyester composition.

In one aspect of the invention, the molded body is preferably a connector.

In one aspect of the invention, the connector is preferably a CPU socket.

1‧‧‧Motor

1a‧‧‧Motorbox

2‧‧‧Cylinder

3‧‧‧ screw

4‧‧‧1st exhaust department

5‧‧‧Main supply port (1st supply port)

6‧‧‧2nd exhaust department

7‧‧‧ side feed port (2nd supply port)

8‧‧‧Transportation Department

9‧‧‧ spit out the die

10‧‧‧Exporting machine

11‧‧‧1st mixing department

12‧‧‧The second mixing department

13‧‧‧3rd mixing department

Fig. 1 is a schematic cross-sectional view showing an extruder used in the method for producing a liquid crystal polyester composition of the present embodiment.

Form for implementing the invention [Liquid crystal polyester composition]

The liquid crystal polyester composition of the present embodiment has a liquid crystal polyester content of 100 parts by mass, a total of 65 parts by mass or more and 100 parts by mass or less of the fibrous filler and the plate-shaped filler, and the fiber-like filler coefficient has an average fiber diameter of 5 μm. The above-mentioned 15 μm or less, and the number average fiber length is longer than 200 μm and less than 400 μm, and the mass ratio of the fibrous filler to the plate-shaped filler (the mass of the fibrous filler/the mass of the plate-shaped filler) is 3 or more. 15 or less, and the flow initiation temperature is 250 ° C or more and less than 314 ° C.

The liquid crystal polyester composition may be a liquid crystal polyester, a fibrous filler, or a plate-shaped filler (mixed powder), or may be processed into a pellet shape by melt-kneading each component.

(liquid crystal polyester)

The liquid crystal polyester of the present embodiment is a liquid crystal polyester which exhibits liquid crystallinity in a molten state, and is preferably melted at a temperature of 450 ° C or lower. The liquid crystal polyester may be a liquid crystal polyester decylamine, a liquid crystal polyester ether, or a liquid crystal polyester carbon. The acid ester may also be a liquid crystal polyester quinone imine. The liquid crystal polyester is preferably a wholly aromatic liquid crystal polyester obtained by using only an aromatic compound as a raw material monomer.

Typical examples of the liquid crystal polyester include, for example, polymerizing at least one compound selected from the group consisting of an aromatic diol, an aromatic hydroxylamine, and an aromatic diamine, and an aromatic hydroxycarboxylic acid and an aromatic dicarboxylic acid. (polycondensation); a mixture of a plurality of aromatic hydroxycarboxylic acids; at least one compound selected from the group consisting of aromatic diols, aromatic hydroxylamines, and aromatic diamines A polymerization of a dicarboxylic acid; and a polymerization of a polyester such as polyethylene terephthalate and an aromatic hydroxycarboxylic acid. Some or all of the aromatic hydroxycarboxylic acid, the aromatic dicarboxylic acid, the aromatic diol, the aromatic hydroxylamine, and the aromatic diamine may be independently substituted with such a polymerizable derivative.

The polymerizable derivative of a compound having a carboxyl group such as an aromatic hydroxycarboxylic acid or an aromatic dicarboxylic acid is exemplified by converting a carboxyl group into an alkoxycarbonyl group or an aryloxycarbonyl group, and converting the carboxyl group into a carboxyl group. A haloformyl group (oxyhalide) and a carboxyl group converted to a fluorenyloxy group (anhydride). Examples of the polymerizable derivative of a compound having a hydroxyl group of an aromatic hydroxycarboxylic acid, an aromatic diol, and an aromatic hydroxyamine are those obtained by deuterating a hydroxy group and converting it into an oxiranyl group (telluride). Examples of the polymerizable derivative of the compound having an amine group of an aromatic hydroxylamine and an aromatic diamine are those obtained by deuteration of an amine group and conversion into a mercapto group.

The liquid crystal polyester preferably has a repeating unit (hereinafter sometimes referred to as "repeating unit (1)") represented by the following formula (1), and more preferably has a repeating unit (1) and has the following formula (2) The repeating unit shown (hereinafter, there are The time is referred to as "repetition unit (2)") and the repetitive unit (hereinafter referred to as "repeating unit (3)") shown by the following formula (3).

(1)-O-Ar ¹ -CO-

(2)-CO-Ar ² -CO-

(3)-X-Ar ³ -Y-

Wherein, Ar ¹ represents a phenylene group, an extended naphthyl group or a stretched biphenyl group; and the Ar ² and Ar ³ groups independently represent a phenylene group, an extended naphthyl group or a stretched phenyl group, or are represented by the following formula (4). The X and Y groups each independently represent an oxygen atom or an imido group (-NH-), and the hydrogen atom of the above group represented by Ar ¹ , Ar ² or Ar ³ may independently be a halogen atom or an alkane. Substituted by aryl or aryl.

(4)-Ar ⁴ -Z-Ar ⁵ -

Here, Ar ⁴ and Ar ⁵ each independently represent a phenyl or anthracene group, and Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group or an alkylene group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the alkyl group include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, t-butyl, n-hexyl, 2-ethylhexyl, It is a octyl group and a ruthenium group. The carbon number of the alkyl group is preferably from 1 to 10.

Examples of the aryl group include a phenyl group, an o-xylylene group, a m-xylylene group, a p-xylylene group, a 1-naphthyl group, and a 2-naphthyl group. The carbon number of the aryl group is preferably from 6 to 20.

When the hydrogen atom of the above-mentioned group represented by Ar ¹ , Ar ² and Ar ^{3 is} substituted with such a group (that is, a halogen atom, an alkyl group and/or an aryl group), the number of groups of the substituted hydrogen atom is attached to Each of the aforementioned groups represented by Ar ¹ , Ar ² or Ar ³ is preferably independently 2 or less, and more preferably 1 each.

Examples of the above alkylene group include a methylene group, an ethylene group, an isopropylidene group, a n-butylene group, and a 2-ethylhexylene group. The carbon number of the alkylene group is preferably from 1 to 10.

The repeating unit (1) is a repeating unit derived from a specific aromatic hydroxycarboxylic acid. The repeating unit (1) is preferably a repeating unit derived from p-hydroxybenzoic acid (Ar ¹ is a para-phenylene group) or a repeating unit derived from 6-hydroxy-2-naphthoic acid (Ar ¹ is 2, 6) - stretching naphthyl).

The repeating unit (2) is a repeating unit derived from a specific aromatic dicarboxylic acid. The repeating unit (2) is preferably Ar ^{2 which} is a phenylene group (reporting unit derived from citric acid), Ar ² is an intermetallic phenyl group (repetitive unit derived from isophthalic acid), and Ar ² is 2,6-anthranyl group (repetitive unit derived from 2,6-naphthalenedicarboxylic acid).

The repeating unit (3) is a repeating unit derived from a specific aromatic diol, an aromatic hydroxylamine or an aromatic diamine. The repeating unit (3) is preferably those in which Ar ³ is a p-phenylene group (reporting unit derived from hydroquinone, p-aminophenol or p-phenylenediamine), and Ar ³ is a 4,4′-extended biphenyl group. (Recovering unit derived from 4,4'-dihydroxybiphenyl, 4-amino-4'-hydroxybiphenyl or 4,4'-diaminobiphenyl).

The content of the repeating unit (1) is a total amount of the total repeating units constituting the liquid crystal polyester (the mass of each of the overlapping units constituting the liquid crystal polyester is divided by the amount of each of the overlapping units, and each weight is obtained. The mass of the covering unit is equivalent (mole), and the value thereof is 100 mol%, preferably 30 mol% or more, more preferably 30 mol% or more and 80 mol% or less, and most preferably 40. Moer % or more is 70 mol% or less, and particularly preferably 45 mol% or more and 65 mol% or less.

The content of the repeating unit (2) is 100 mol% of the total re-equipment unit constituting the liquid crystal polyester, preferably 35 mol% or less, more preferably 10 mol% or more and 35 mol% or less, most It is preferably 15 mol% or more and 30 mol% or less, and particularly preferably 17.5 mol% or more and 27.5 mol% or less.

The content of the repeating unit (3) is 100 mol% of the total re-equipment unit constituting the liquid crystal polyester, preferably 35 mol% or less, more preferably 10 mol% or more and 35 mol% or less, most It is preferably 15 mol% or more and 30 mol% or less, and particularly preferably 17.5 mol% or more and 27.5 mol% or less.

The more the content of the repeating unit (1), the tendency of the liquid crystal polyester to have melt flowability, heat resistance, strength, and rigidity. However, when the content of the repeating unit (1) exceeds 80 mol%, the melting temperature or the melt viscosity tends to be high, and the temperature necessary for molding tends to be high.

The ratio of the content of the repeating unit (2) to the content of the repeating unit (3) is expressed by [the content of the repeating unit (2)] / [the content of the repeating unit (3)] (mol/mole) It should be 0.9/1~1/0.9, more preferably 0.95/1~1/0.95, and most preferably 0.98/1~1/0.98.

The liquid crystal polyester may independently have two or more types of overlapping units (1) to (3). Further, the liquid crystal polyester may have a repetitive unit other than the repeating units (1) to (3), and the content thereof is such that the total amount of the full resurfacing units is 100 mol%, preferably 0 mol% or more. The molar percentage is below, more preferably 0% by mole or more and 5% by mole or less.

In order to reduce the melt viscosity of the liquid crystal polyester, it is preferred to be a repeating unit (3) X and Y are each an oxygen atom (i.e., a repeating unit derived from an aromatic diol). By increasing the amount of the oxygen atom's repeating unit (3) by X and Y, respectively, the melt viscosity of the liquid crystal polyester is lowered, so that the amount of the repetitive unit (3) in which X and Y are respectively oxygen atoms can be controlled as needed. The melt viscosity of the liquid crystal polyester can be adjusted.

The liquid crystal polyester is preferably produced by melt-polymerizing a raw material monomer corresponding to a repeating unit constituting the liquid crystal polyester, and solid-phase polymerizing the obtained polymer (prepolymer). Thereby, a high molecular weight liquid crystal polyester having high heat resistance or high strength rigidity can be produced with good operability, so that the melt polymerization can be carried out in the presence of a catalyst. Examples of the catalyst include metal compounds such as magnesium acetate, first tin acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide, or, for example, 4-(dimethylamino). A nitrogen-containing heterocyclic compound of pyridine and 1-methylimidazole, wherein a nitrogen-containing heterocyclic compound is preferred.

The flow start temperature of the liquid crystal polyester can be appropriately adjusted according to the flow start temperature of the liquid crystal polyester composition to be described later. The flow initiation temperature of the liquid crystal polyester composition strongly depends on the flow start temperature of the resin component (liquid crystal polyester) serving as the substrate, and the addition of the filler does not change. Therefore, in order to allow the flow start temperature of the liquid crystal polyester composition to be contained in a temperature range of 250 ° C or more and less than 314 ° C, the flow start temperature of the liquid crystal polyester composition is controlled. The details will be described later.

The flow initiation temperature is also called the Flow temperature or the flow temperature, and is the standard temperature of the molecular weight of the liquid crystal polyester (refer to Xiao Chongzhi, "Liquid Crystal Polymer-Synthesis, Forming, Application-", the company CMC, 1987 June 5, p.95). The flow start temperature was measured by using a flow tester ("CFT-500 type" manufactured by Shimadzu Corporation), and about 2 g of liquid crystal polyester was filled in a cylinder in which a die having a nozzle having an inner diameter of 1 mm and a length of 10 mm was mounted, 9.8 Under the load of MPa (100kgf/cm ² ), the temperature is raised at a rate of 4 ° C / min, and the liquid crystal polyester is melted and extruded from the nozzle, and the measurement shows 4800 Pa. The method of measuring the viscosity (flow start temperature) of s (48000 poise).

(fibrous filler)

The fibrous filler material contained in the liquid crystal polyester composition of the present embodiment has an average fiber diameter of 5 μm or more and 15 μm or less, and the number average fiber length is longer than 200 μm and less than 400 μm, and the number average fiber length is preferably 200 μm. The length is 350 μm or less, and more preferably 200 μm long and 300 μm or less. By the number average fiber length of the fibrous filler in the liquid crystal polyester composition being such a length, the crucible of the molded body composed of the obtained liquid crystal polyester composition can be improved, and the burr can be suppressed With short hair.

The number average fiber diameter and the number average fiber length can be determined by observation with an electron microscope. Explain the specific method below.

First, 1.0 g of a resin composition was placed in a mortar and ashed in an electric furnace at 600 ° C for 4 hours to obtain a residue containing a fibrous filler. A photomicrograph of the state in which the residue was dispersed in methanol to develop on the watch glass. Then, from the obtained microscope photograph, the projection image of the fibrous filler from the visual field direction is read as the fiber length in the longitudinal direction, and the fiber diameter is read as the fiber diameter in the direction perpendicular to the longitudinal direction to calculate the arithmetic. average The value is found. When the average value is calculated, the denominator is 400 or more.

As the fibrous filler, either or both of a fibrous inorganic filler and a fibrous organic filler can be used. The fibrous inorganic filler may be exemplified by glass fibers; carbon fibers such as PAN-based carbon fibers and Pitch-based carbon fibers; ceramic fibers such as cerium oxide fibers, alumina fibers, and cerium oxide alumina fibers; metal fibers such as stainless steel fibers; Such as potassium titanate whiskers, barium titanate whiskers, ettringite whiskers, aluminum borate whiskers, tantalum nitride whiskers and whiskers of tantalum carbide whiskers. Among them, one or more kinds of fibrous fillers selected from the group consisting of glass fibers, potassium titanate whiskers, ettringite whiskers, and aluminum borate whiskers are preferable, and glass fibers are more preferable.

(plate filler)

The plate-shaped filler contained in the liquid crystal polyester composition of the present embodiment is preferably an inorganic filler. The plate-shaped inorganic filler is exemplified by one or more kinds of plate-shaped fillers selected from the group consisting of talc, mica, graphite, ettringite, glass flakes, barium sulfate, and calcium carbonate. Among them, it is preferably either or both of talc and mica, and more preferably talc.

The volume average particle diameter of the plate-shaped filler contained in the liquid crystal polyester composition of the present embodiment is improved by the crack resistance of the molded article composed of the liquid crystal polyester composition, and is preferably 10 μm or more and 30 μm or less. It is preferably 10 μm or more and 20 μm or less.

The volume average particle diameter of the plate-shaped filler can be determined by observation with an electron microscope. Explain the specific method below.

First, take 1.0 g of the resin composition in a mortar and make 600 in an electric furnace. After the treatment at ° C for 4 hours, ashing was carried out to obtain a residue containing a plate-shaped filler. A photomicrograph of the state in which the residue was dispersed in methanol to develop on the watch glass. Then, from the obtained microscope photograph, the area is obtained from the projection image of the plate-shaped filler from the visual field direction, and the diameter of the circle (the diameter of the equivalent area circle) when the circle having the same area is assumed is read as The particle size of the plate-shaped filler was determined by calculating an arithmetic mean value. When the average value is calculated, the denominator is 400 or more.

The volume average particle diameter of the plate-shaped filler is substantially unchanged by melt-kneading described later, and the volume average particle diameter of the plate-shaped filler can also be measured by the plate-like filling before the liquid crystal polyester composition is contained. The volume average particle diameter of the material was determined.

(liquid crystal polyester composition)

In the liquid crystal polyester composition of the present embodiment, the total amount of the liquid crystal polyester is 100 parts by mass or less, and the total amount of the fibrous filler and the plate-shaped filler is 65 parts by mass or more and 100 parts by mass or less. When the total amount of the fibrous filler and the plate-like filler is 100 parts by mass of the liquid crystal polyester, it is preferably 65 parts by mass or more and 90 parts by mass or less, more preferably 70 parts by mass or more and 90 parts by mass or less.

When the total amount of the fibrous filler and the plate-shaped filler is 65 parts by mass or more, the molded article composed of the liquid crystal polyester composition has a large effect of improving crack resistance and warpage reduction. When the total amount of the fibrous filler and the plate-like filler is 100 parts by mass or less, the melt fluidity of the liquid crystal polyester composition becomes sufficient.

In the liquid crystal polyester composition, the mass ratio of the fibrous filler to the plate-shaped filler is 3 or more and 15 or less. The quality of the fibrous filler to the plate-shaped filler is preferably 3 or more and 10 or less, more preferably 4 or more and 7 or less. When the mass ratio is in the above range, a molded article having a thin portion and having a welded portion can be obtained, and when it is used alone as either a plate-shaped filler or a fibrous filler, it is particularly excellent in crack resistance. Sexuality and good flow balance.

Further, in the liquid crystal polyester composition, the flow initiation temperature is 250 ° C or more and less than 314 ° C. The flow initiation temperature of the liquid crystal polyester composition is preferably 260 ° C or more and 310 ° C or less, more preferably 280 ° C or more and 310 ° C or less. When the flow start temperature is lower than 250 ° C, when an electronic device is produced using a molded body composed of a liquid crystal polyester composition, it may not be able to withstand the heat treatment at a high temperature in the reflow step and be damaged. When the flow initiation temperature is higher than 314 ° C, the crack resistance of the molded body composed of the liquid crystal polyester composition is lowered.

The flow initiation temperature of the liquid crystal polyester composition can be adjusted by controlling the content of the fibrous filler and the plate filler and the flow start temperature of the liquid crystal polyester.

Among them, the flow initiation temperature of the liquid crystal polyester composition strongly depends on the flow start temperature of the resin component serving as the substrate. Therefore, a liquid crystal polyester having an appropriate flow initiation temperature is selected in accordance with the content of the fibrous filler and the plate-like filler, and a liquid crystal polyester composition exhibiting a flow start temperature for the purpose can be obtained.

In other words, the amount of the filler (the fibrous filler and the plate filler) added to the liquid crystal polyester is 65 parts by mass or more and 100 parts by mass or less. When the range is changed, the flow initiation temperature of the liquid crystal polyester composition generally varies from -15 ° C to + 15 ° C. Therefore, when the flow start temperature of the liquid crystal polyester composition is 250 ° C or more and less than 314 ° C, a liquid crystal polyester having a flow start temperature of 235 ° C or more and less than 329 ° C can be used. More preferably, the flow initiation temperature of the liquid crystal polyester composition is 265 ° C or more and less than 299 ° C.

The liquid crystal polyester may be one type or a mixture of two or more types of liquid crystal polyesters having different flow initiation temperatures. When the liquid crystal polyester is a mixture of two or more kinds of liquid crystal polyesters, the flow start temperature of the mixture of the liquid crystal polyesters is controlled so that the flow start temperature of the liquid crystal polyester composition is 250 ° C or more and less than 314 ° C.

The flow initiation temperature of the mixture of the liquid crystal polyesters can be estimated by forming an average of the weights of the flow start temperatures of the respective liquid crystal polyesters according to the blend ratio of the liquid crystal polyesters contained in the mixture. Therefore, for the target flow initiation temperature, a liquid crystal polyester having a high flow initiation temperature and a liquid crystal polyester having a low flow initiation temperature can be mixed, and a mixture of liquid crystal polyesters having a desired flow initiation temperature can be adjusted.

The liquid crystal polyester used in the liquid crystal polyester composition of the present embodiment is composed of a liquid crystal polyester (A) and a liquid crystal polyester (B), and the liquid crystal polyester (A) is represented by the above formula (1). The repeating unit, the repeating unit represented by the above formula (2), and the repeating unit represented by the above formula (3), wherein Ar ¹ in the formula (1) is a para-phenyl group, a liquid crystal polyester ( B) is composed of a repeating unit represented by the above formula (1), a repeating unit represented by the above formula (2), and a repeating unit represented by the above formula (3), and In 1), Ar ¹ is a 2,6-anthranyl group.

In the liquid crystal polyester composition using the liquid crystal polyester (A) and the liquid crystal polyester (B), a molded body in which cracking of the molded body is more difficult to occur can be obtained.

When the liquid crystal polyester is composed of the liquid crystal polyester (A) and the liquid crystal polyester (B), it is preferable to contain 20 parts by mass or more of the liquid crystal polyester (A) in 100 parts by mass of the liquid crystal polyester. The liquid crystal polyester preferably contains 20 parts by mass or more and less than 100 parts by mass of the liquid crystal polyester (A), and most preferably contains 45 parts by mass or more and 95 parts by mass or less, more preferably 70 parts by mass or more and 95 parts by mass or less.

(other ingredients)

The liquid crystal polyester composition of the present embodiment may contain an additive and/or a resin component other than the liquid crystal polyester, insofar as the effects of the present invention are not impaired. The additive which can be contained in the liquid crystal polyester composition is exemplified by an antioxidant, a thermal stabilizer, an ultraviolet absorber, an antistatic agent, a surfactant, a flame retardant, and a color former. The blending ratio of the additive is 0 parts by mass or more and 5 parts by mass or less based on 100 parts by mass of the liquid crystal polyester.

The resin component other than the liquid crystal polyester which the liquid crystal polyester composition may contain may, for example, be a polyester other than polypropylene, polyamide or liquid crystal polyester, polyfluorene, polyphenylene sulfide, polyether ketone, polycarbonate, or the like. A thermoplastic resin of polyphenylene ether and polyetherimine; and a thermosetting resin of a phenol resin, an epoxy resin, a polyimide resin, and a cyanate resin. The blending ratio of the resin component is 0 parts by mass or more and 20 parts by mass or less based on 100 parts by mass of the liquid crystal polyester.

(Method for producing liquid crystal polyester composition)

In the method for producing a liquid crystal polyester composition of the present embodiment, a mixture of 65 parts by mass or more and 100 parts by mass or less of the total of the fibrous filler material and the plate-shaped filler is melted and kneaded. The steps.

The filler raw material coefficient average fiber diameter used in the method for producing a liquid crystal polyester composition of the present embodiment is 5 μm or more and 15 μm or less, and the number average aspect ratio is 100 or more. The filler raw material coefficient has an average fiber diameter of 5 μm or more and 15 μm or less, and the number average fiber length is 1 mm or more and 3 mm or less. As the filler raw material, a constituent material similar to the above-described fibrous filler can be used.

The extruder used in the step of melt kneading includes a cylinder barrel and a screw provided in the cylinder barrel. The cylinder tube has a first supply port and a second supply port located on the downstream side in the direction of the extrusion from the first supply port. The cylinder is preferably one or more exhaust units.

The ratio (L/D) of the effective length (L) of the screw system screw to the diameter (D) of the screw is 15 or more and 65 or less.

The "diameter of the screw" is the "outer diameter of the screw", that is, the reference dimension of the outer diameter of the screw at the tip end of the screw. The "effective length of the screw" is the "length in the axial direction of the groove of the screw", that is, the length in the axial direction of the portion in which the groove is provided in the screw.

In the method for producing a liquid crystal polyester composition of the present embodiment, 50% by mass or more of the total supply amount of the liquid crystal polyester is supplied from the first supply port, and the filling is performed. 50% by mass or less of the total supply amount of the material is supplied, and the residual amount of the liquid crystal polyester, the residual amount of the filler material, and the total amount of the plate-shaped filler are supplied from the second supply port to be melted and kneaded.

Hereinafter, a method for producing a liquid crystal polyester composition of the present embodiment will be specifically described using the drawings. Fig. 1 is a schematic cross-sectional view showing an extruder used in a method for producing a liquid crystal polyester composition.

The extruder 10 shown in FIG. 1 includes a motor 1 housed in a motor case 1a, a cylinder 2 provided adjacent to the motor case 1a, and a screw 3 inserted into the cylinder 2 and connected to the motor 1. The extruder 10 is a two-axis extruder in which two screws 3 are disposed in the cylinder 2.

The cylinder tube 2 is provided with a part for supplying a liquid crystal polyester, a filler material, a plate-shaped filler, and other components (hereinafter, referred to as "raw material components") as needed. The main supply port (first supply port) 5, the downstream side (rear) in the direction in which the main supply port 5 is pushed out, and the side supply port for supplying the residual portion of the raw material component in the inside of the cylinder tube 2 (second supply) Port 7: a first exhaust unit 4 and a second exhaust unit 6 for discharging volatile components (gas) generated in the cylinder 2, and a discharge die for kneading and kneading the obtained kneaded material 9.

The main feed port 5 is provided at the position where the screw 2 is at the uppermost flow direction (the position on the motor case 1 side), and is directed from the main supply port 5 to the downstream side in the extrusion direction (the rear side in the extrusion direction, that is, the discharge die 9 side). The side supply port 7, the first deaeration portion 4, and the second deaeration portion 6 are provided in this order, and the end portion on the downstream side in the direction of the extrusion of the screw 2 is provided with the discharge of the nozzle hole 9a communicating with the cylinder tube 2. Die 9. Cylinder 2 is to suppress shear heat, and cylinder temperature should be performed. Full control.

The main supply port 5 and the side supply port 7 have a supply hopper connected to the inside of the cylinder tube 2 and a supply device for supplying a raw material component in a constant mass or a fixed capacity. Examples of the supply method of the supply device include, for example, a degassing type, a screw type, a vibration type, and a table top.

The first deaeration unit 4 and the second deaeration unit 6 may be open to the atmosphere, or may be connected to a water-sealed pump, a rotary pump, an oil diffusion pump, or a turbo pump. Wait until the vacuum is removed from the vacuum.

The screw 3 is L/D of 15 or more and 65 or less, and is provided with a conveying unit 8 for conveying a raw material component or a kneaded material. Further, the first kneading portion 11 is provided between the main supply port 5 and the side supply port 7 in the screw 3, and the second kneading portion 12 is provided between the side supply port 7 and the first exhaust portion 4. The third kneading portion 13 is provided between the first exhaust unit 4 and the second exhaust unit 6. The first kneading section 11 to the third kneading section 13 are configured to perform plasticization and kneading of the raw material component or the kneaded material, respectively. Further, the screw 3 system is provided with another kneading section.

Such a screw 3 is constructed by combining screw elements. The general conveying unit 8 is a screw element of a thread (full thread), and the first kneading unit 11, the second kneading unit 12, and the third kneading unit 13 are full-thread, reverse-thread, sealing ring, kneading disc, and medium-kneading disc. It is composed of a combination of screw elements such as a reverse kneading disc.

As the first kneading section 11, the second kneading section 12, and the third kneading section 13, it is preferable to use a component in which the kneading disc is shifted so that the phase angle is larger than 0 and less than 90 degrees, and the overlapping components are combined with the middle kneading. Element (composition that the kneading discs are overlapped by a phase angle of 90 degrees).

The other components constituting the screw 3 may be any screw element as long as the entire conveyance of the melted kneaded material is not lost.

The extruder used in the present embodiment is not limited to the two-axis extruder shown in Fig. 1, and may be a short-axis extruder. The example of the two-axis extruder is one thread that rotates from the same direction to three threads, the parallel shaft type that rotates in the opposite direction, the oblique axis type, or the incompletely bite type, but it is preferable to rotate the two shafts in the same direction. machine.

The extruder described here is not limited to one of the users in the present embodiment, and various known extruders can be used.

In the method for producing a liquid crystal polyester of the present embodiment, the extruder is used, and 50% by mass or more of the total supply amount of the liquid crystal polyester is supplied from the main supply port 5, and 50% by mass of the total supply amount of the filler material is supplied. Hereinafter, the residual amount of the liquid crystal polyester, the residual amount of the filler raw material, and the total amount of the plate-shaped filler are supplied from the side supply port 7 to be melted and kneaded. Thereby, the following effects can be obtained.

In general, in the melt kneading using an extruder, the filler material is broken in the extruder, and the number average fiber length tends to be short. Therefore, in the general melt kneading, the fibrous filler is supplied from the flow side (second supply port) of the extruder, and the time of kneading in the extruder is shortened, and the variation of the average fiber length of the fibrous filler is reduced. .

On the other hand, in the method for producing a liquid crystal polyester composition of the present embodiment, a part of the filler material is supplied from the first supply port together with the liquid crystal polyester, and the time for kneading in the extruder is actively increased. Thereby, the filler raw material is broken during the extrusion processing, and a fibrous filler having a number average fiber length of 200 μm and less than 400 μm can be formed.

A fibrous filler having a number average fiber length of 200 μm and less than 400 μm is difficult to handle because of minute fibers. However, in the production method of the present embodiment, since the number average fiber length of the fibrous filler can be controlled during melt-kneading, it is not necessary to use a blending operation of a minute fibrous filler, and the desired liquid crystal polymerization can be easily produced. Ester composition.

The processing conditions must be changed depending on the type or blending of the filler raw materials to be used, but the processing conditions and the number average fiber length of the fibrous filler contained in the obtained liquid crystal polyester are confirmed by preliminary experiments. Relationships can be set as appropriate.

For example, when the fiber-like filler obtained by a certain processing condition (referred to as "reference condition" in the following description) is used as a reference, and the number average fiber length of the fibrous filler is shortened, it is preferable to increase the reference condition. The ratio of the filler material supplied from the first supply port. Further, even by using a screw having an L/D larger than the reference condition, the number average fiber length of the fibrous filler can be shortened. Further, even if the cylinder temperature is lowered by the more basic conditions, the shearing force of the screw becomes higher, and the number average fiber length of the fibrous filler can be shortened. Further, the amount of discharge per unit time is reduced, and the kneading time becomes long, and the number average fiber length of the fibrous filler can be shortened.

The number average fiber diameter of the filler raw material and the volume average particle diameter of the plate-shaped filler are not substantially changed by melt kneading. Therefore, the number average fiber diameter of the filler raw material and the volume average particle diameter of the plate-shaped filler can be used as the number average fiber diameter of the fibrous filler contained in the obtained liquid crystal polyester composition, and the plate-like filling. The volume average particle size of the material is substantially the same.

(formed body)

The molding system of the present embodiment can be obtained by injection molding of a liquid crystal polyester composition produced by the above-described liquid crystal polyester composition or the above-described method for producing a liquid crystal polyester composition.

In the injection molding system, an injection molding machine (for example, "Electrical Horizontal Forming Machine ES 400 Model" manufactured by Nissei Resin Co., Ltd.) is used to melt the liquid crystal polyester composition described above, and the molten liquid crystal polyester composition is heated to an appropriate temperature. The temperature is applied to the mold having the desired cavity shape.

The forming system can be exemplified as a frame of an optical pickup frame and a transformer frame; for example, a relay case, a relay base, a relay bobbin, and a relay pivot type relay part; such as a RIMM, DDR, I/O, DIMM, board-to-board connector, FPC connector, card connector and CPU socket connector; such as lamp reflector and LED reflector reflector; such as lamp support and heater support seat; such as the vibrating plate of the vibrating plate; such as photocopying Machine separation claws and separation claws for separation claws for printers; camera module parts; switch parts; motor parts; sensor parts; hard disk drive parts; oven foods; vehicle parts; aircraft parts; A sealing member for a sealing member and a sealing member for a coil.

In particular, the liquid crystal polyester composition of the present embodiment can be suitably molded into a molded body having a thin meat portion or a molded body having a complicated shape, and can have a molded article having excellent crack resistance and suppressing burrs or short hair. Used as a material for connectors such as CPU sockets.

A connector formed using the above liquid crystal polyester composition is, for example, In the reflow step, even when heated, cracking can be suppressed.

According to the liquid crystal polyester composition having the above-described structure, the crack resistance of the formed molded article and the favorable flow balance at the time of melt processing can be exhibited, and an excellent molded body can be obtained.

Further, according to the method for producing a liquid crystal polyester composition as described above, the number average fiber length of the fibrous filler can be controlled during the processing, and the liquid crystal polyester composition as described above can be easily produced.

Further, in the case of the above-mentioned molded body, the crack resistance is excellent, and it is possible to suppress burrs and short hair.

Example

The invention is illustrated by the following examples, but the invention is not limited to the examples. Further, in the present embodiment, the measurement was carried out in the following manner.

(Measurement of flow start temperature of liquid crystal polyester and liquid crystal polyester composition)

The flow start temperature of the liquid crystal polyester was measured by using a flow tester (manufactured by Shimadzu Corporation, model CFT-500), and about 2 g of the liquid crystal polyester was filled in a cylinder in which a die having a nozzle having an inner diameter of 1 mm and a length of 10 mm was mounted. Under the load of 9.8 MPa (100 kgf/cm ² ), the temperature was raised at a rate of 4 ° C / min, and the liquid crystal polyester was melted and extruded from the nozzle, and the measurement showed 4800 Pa. The temperature of the viscosity of s (48000 poise) is obtained.

The flow initiation temperature of the liquid crystal polyester composition was determined by measuring the liquid crystal polyester as described above in the same manner as the liquid crystal polyester composition.

(Measurement of the number average fiber length and the number average fiber diameter of the fibrous filler)

1.0 g of a liquid crystal polyester composition was placed in a mortar, and ashed in an electric furnace at 600 ° C for 4 hours to obtain a residue containing a fibrous filler. A photomicrograph of the state in which the residue was dispersed in methanol to develop on the watch glass. Then, in the projection image of the fibrous filler from the field of view obtained from the micrograph, the length in the long direction is read as the fiber length, and the length in the direction orthogonal to the longitudinal direction is read as the fiber diameter to calculate the arithmetic mean. The value is found. When calculating the average value, the denominator is set to 400.

(Measurement of Volume Average Particle Diameter of Plate Filler in Liquid Crystal Polyester Composition)

1.0 g of a liquid crystal polyester composition was placed in a mortar and pulverized by treatment in an electric furnace at 600 ° C for 4 hours to obtain a residue containing a plate-shaped filler. A photomicrograph of the state in which the residue was dispersed in methanol to develop on the watch glass. Then, the area obtained from the projection image of the plate-shaped filler from the field of view is obtained from the micrograph, and the diameter (the diameter of the circle of the area) when the circle having the same area is assumed is read as the plate-like filling. The particle size of the material was determined by calculating an arithmetic mean value. When calculating the average value, the denominator is set to 400.

(Measurement of crack of molded body)

The crack of the molded body was measured in the following manner.

First, prepare five injection molded bodies to be described later (corresponding to 1021 pins) The pattern CPU socket) was heated at 260 ° C for 4 minutes and 40 seconds using an oven (manufactured by Yamato Scientific Co., Ltd., DN63H), and a heat history was added to the five molded bodies. This temperature condition is a temperature condition of a reflow step when an electronic machine is manufactured using a CPU socket.

After the molded body was allowed to cool to room temperature, a 15-fold zoom solid microscope (Sigma-made machine, ZMM-45T2) was used, and a sample of the molded product 5 was observed, and a turtle was measured on the wall surface of the CPU socket. The number of cracks is such that the total value is taken as the number of cracks.

In the present embodiment, the level in which the number of cracks in the 1021 holes of the CPU socket is less than 1% is evaluated as good. That is, the number of cracks per allowable for the CPU socket is about 10, and the total number of cracks generated by the five CPU sockets is preferably 50 or less.

(Evaluation of the burrs and short hair of the formed body)

The burrs and the short hair of the molded body are observed on the surface of the injection molded body (the CPU socket corresponding to the 1021 pin) which is described later, using a zoom-type solid microscope (Sigma-made machine, ZMM-45T2) having a magnification of 10 times. Evaluation.

The evaluation of the burrs is performed by observing all the holes of the CPU socket filled with the resin by a microscope, and if the hole is formed with no burrs relative to the opening area of the hole to about 20%, it is evaluated as "○", as long as there is one, that is, The assessment is "X".

The evaluation of the short hair is to confirm the final filling position of the molten resin in the CPU socket in advance, and observe the CPU formed by each resin composition by a microscope. If the final filling position of the socket is completely filled with resin, it is "○", and if there is a depression due to insufficient filling, the amount of depression is "x" regardless of the amount of depression.

(Reference Example 1: Production of Liquid Crystal Polyester (1))

In a reactor equipped with a stirring device, a torque meter, a nitrogen gas introduction tube, a thermometer and a reflux cooler, 994.5 g (7.2 mol) of p-hydroxybenzoic acid, 239.2 g (1.44 mol) of p-phthalic acid, and isodecanoic acid were placed. 159.5g (0.96 moles), 4,4'-dihydroxybiphenyl 446.9g (2.4 moles) and acetic anhydride 1347.6g (13.2 moles), after replacing the gas in the reactor with nitrogen, add 1-a 0.18 g of imidazole was heated under a nitrogen gas stream for 30 minutes from room temperature to 150 ° C, and refluxed at 150 ° C for 30 minutes.

Then, 2.4 g of 1-methylimidazole was added, and acetic acid and unreacted acetic anhydride were distilled off, and the temperature was raised from 150 ° C to 320 ° C for 2 hours and 50 minutes, and the time from the rise of the torque was observed from the reactor. The contents were taken out and cooled to room temperature.

The obtained solid matter was pulverized by a pulverizer, and the temperature was raised from room temperature to 220 ° C for 1 hour under nitrogen atmosphere, and the temperature was raised from 220 ° C to 240 ° C for 30 minutes, and maintained at 240 ° C for 10 hours. After solid phase polymerization, cooling was performed. A powdery liquid crystal polyester (1) was obtained. The flow initiation temperature of the liquid crystal polyester (1) was 286 °C.

(Reference Example 2: Production of Liquid Crystal Polyester (2))

The amount of citric acid used was 299.0 g (1.8 mol), isophthalic acid The amount of use is 99.7g (0.6m), the conditions of solid phase polymerization after pulverization, the temperature is raised from room temperature to 250 ° C for 1 hour under nitrogen atmosphere, and the temperature is raised from 250 ° C to 295 ° C for 5 hours to 295 ° C. The remaining liquid crystal polyester (2) was obtained in the same manner as in Reference Example 1 except that it was kept for 3 hours. The flow start temperature of the liquid crystal polyester (2) was 327 °C.

(Reference Example 3: Production of Liquid Crystal Polyester (3))

In the same reaction vessel as in Reference Example 1, 103.99 g (5.5 mol) of 2-hydroxy-6-naphthoic acid, 272.52 g (2.475 mol) of hydroquinone, and 378.33 g of 2,6-naphthalenedicarboxylic acid (1.75) were added. Mohr), 83.07g (0.5mol) of citric acid, 1226.87g (11.9m) of acetic anhydride, after replacing the gas in the reactor with nitrogen, adding 0.17g of 1-methylimidazole, stirring under nitrogen gas flow Warming up on one side. When the internal temperature became 145 ° C, the temperature was directly maintained at the same temperature and stirred for 1 hour.

Next, while distilling off the produced by-produced acetic acid and unreacted acetic anhydride, the temperature was raised from 145 ° C to 310 ° C for 3 hours and 30 minutes. The liquid crystal polyester was obtained by keeping at the same temperature for 3 hours. The obtained liquid crystal polyester was cooled to room temperature, and pulverized by a pulverizer to obtain a powder (prepolymer) of a liquid crystal polyester having a particle diameter of about 0.1 to 1 mm. The obtained powder was heated from 25 ° C to 250 ° C for 1 hour, and then heated from the same temperature to 310 ° C for 10 hours, and then kept at the same temperature for 5 hours to carry out solid phase polymerization.

Thereafter, the solid phase polymerized powder was cooled to obtain a powdery liquid crystal polyester (3). The flow initiation temperature of the liquid crystal polyester (3) was 333 °C.

(Examples 1 to 13 and Comparative Examples 1 to 6)

Liquid crystal polyester (1), (2), (3), short glass fiber (made by Asahi Glass Glass, CS 03 JAPX-1, number average fiber diameter 10 μm, number average fiber length 3 mm, number average length and width Than 300), talc (Japanese talc (stock) system, MS-KY, volume average particle size 14.2 μm), using the ratio shown in Tables 2 and 3, using a twin-axis extruder (pool ironwork) PCM-30HS, screw rotation: same direction, L/D=44), melt-kneaded at 340 °C, pelletized.

Further, the volume average particle diameter of the talc before the granulation described above is a value measured by a laser diffraction method.

In Examples 1 to 13 and Comparative Examples 1 to 3, 5 and 6, 15% by mass of the total supply amount of the liquid crystal polyester and 15% by mass of the total supply amount of the short glass fibers were supplied from the extruder upper portion supply port. The supply was such that 45 mass% of the total supply amount of the liquid crystal polyester and 85 mass% of the total supply amount of the short glass fibers and the total supply amount of the talc were supplied from the flow side supply port below the extruder.

In Comparative Example 4, the total supply amount of the liquid crystal polyester was supplied from the upper portion of the extruder, and the total supply amount of the short glass fibers and the total supply amount of the talc were supplied from the flow side supply port of the extruder.

The injection molding machine (manufactured by Nissei Resin Co., Ltd., ES 400) was used to mold the obtained plastic pellets under the molding conditions of a cylinder temperature of 340 ° C and a mold temperature of 65 ° C to obtain a model CPU socket molded body corresponding to the 1021 pin. .

It was confirmed that the volume average particle diameter of the talc (plate-shaped filler) contained in the CPU socket molded body of the first embodiment was measured as 14.6. Μm is included in the range of 10 μm or more and 30 μm or less.

Regarding the obtained CPU socket, the crack, the burr, and the short hair were evaluated in the above manner. The results of the evaluation are shown in Tables 1 and 2 below.

As a result of the table, the CPU sockets obtained in Examples 1 to 13 were less cracked, and it was also possible to suppress a good molded body in which burrs and short hairs were generated. The CPU sockets obtained in Examples 12 and 13 were not cracked at all, and were excellent in heat resistance.

However, the CPU sockets obtained in Comparative Examples 1 to 3 and 5 often cracked and became poor in crack resistance. In Comparative Example 4, the series 6 produced burrs or short hairs, and did not become a good molded body worthy of evaluation of cracking.

As a result of the above, it was confirmed that the liquid crystal polyester composition of the present invention exhibits both crack resistance and good flow balance, and an excellent molded article is obtained, and it is understood that the obtained molded article has excellent physical property balance. . Moreover, the liquid crystal polyester composition can be easily produced by the method for producing a liquid crystal polyester composition of the present invention.

Industrial use possibility

According to the present invention, it is possible to provide a liquid crystal polyester composition which is resistant to cracking and good flow balance and which can provide an excellent molded body. Further, a method for producing such a liquid crystal polyester composition and a molded body formed by using the liquid crystal polyester composition can be provided.

Claims (11)

A liquid crystal polyester composition comprising 100 parts by mass of a liquid crystal polyester, and a total of 65 parts by mass or more and 100 parts by mass or less of the fibrous filler and the plate-like filler, and the fiber-like filler coefficient has an average fiber diameter of 5 μm or more. The number average fiber length is 15 μm or less and the fiber length is less than 400 μm, and the mass ratio of the fibrous filler to the plate-shaped filler is 3 or more and 15 or less, and the flow initiation temperature is 250° C. or more and less than 314° C. The liquid crystal polyester composition according to claim 1, wherein the liquid crystal polyester has a repeating unit represented by the following formula (1), a repeating unit represented by the following formula (2), and the following formula (3) ) the repeating unit shown; (1)-O-Ar ¹ -CO-(2)-CO-Ar ² -CO-(3)-X-Ar ³ -Y- where Ar ¹ represents benzene a group, an anthranyl group or a biphenyl group; the Ar ² and Ar ³ groups each independently represent a phenyl group, a naphthyl group or a phenyl group or a group represented by the following formula (4), wherein the X and Y groups are respectively The oxygen atom or the imine group is independently represented, and the hydrogen atom of the aforementioned group represented by Ar ¹ , Ar ² or Ar ³ may be independently substituted with a halogen atom, an alkyl group or an aryl group; (4)-Ar ⁴ - Z-Ar ⁵ - Here, Ar ⁴ and Ar ⁵ each independently represent a phenyl or anthracene group, and Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group or an alkylene group. The liquid crystal polyester composition of claim 2, wherein the liquid crystal polyester is a repeating unit represented by the above formula (1), a repeating unit represented by the above formula (2), and the above formula (3) The repeating unit is configured, and the Ar ¹ is a liquid crystal polyester (A) with a phenyl group and a repeating unit represented by the above formula (1), and is represented by the above formula (2). The repeating unit is composed of a repeating unit represented by the above formula (3), and the above Ar ¹ is a mixture of the liquid crystal polyester (B) of 2,6-anthranyl group. The liquid crystal polyester composition of claim 3, wherein the liquid crystal polyester (A) is contained in an amount of 20 parts by mass or more based on 100 parts by mass of the liquid crystal polyester. The liquid crystal polyester composition according to any one of claims 1 to 4, wherein the fibrous filler is selected from the group consisting of glass fiber, ettringite whisker, aluminum borate whisker and potassium titanate whisker. At least one of them. The liquid crystal polyester composition according to any one of claims 1 to 4, wherein the plate-shaped filler is one or both of mica and talc. The liquid crystal polyester composition according to any one of claims 1 to 4, wherein the plate-shaped filler has a volume average particle diameter of 10 μm or more and 30 μm or less. A method for producing a liquid crystal polyester composition, comprising the steps of: melt-kneading a mixture containing 65 parts by mass of the liquid crystal polyester and 65 parts by mass or more and 100 parts by mass or less of the total of the fibrous filler raw material and the plate-shaped filler; The filler material coefficient has an average fiber diameter of 5 μm or more and 15 μm or less and a number average aspect ratio of 100 or more. The extruder used in the step of melt kneading includes a cylinder barrel and a screw provided in the cylinder barrel, and the cylinder The tubular system has a first supply port and is more than the first supply port a second supply port located on the downstream side in the extrusion direction; a ratio (L/D) of the effective length (L) of the screw-type screw to the diameter (D) of the screw is 15 or more and 65 or less, and the liquid crystal is supplied from the first supply port 50% by mass or more of the total supply amount of the polyester and 50% by mass or less of the total supply amount of the filler raw material, and the residual amount of the liquid crystal polyester and the residual amount of the filler raw material are supplied from the second supply port The entire amount of the plate-shaped filler is melted and kneaded. A molded article which is obtained by the liquid crystal polyester composition of any one of claims 1 to 7 or the liquid crystal polyester composition produced by the method for producing a liquid crystal polyester composition according to claim 8. It is obtained by injection molding. The formed body of claim 9, wherein the shaped body is a connector. The molded body of claim 10, wherein the connector is a CPU socket.